[43.09] The Most Curious Case of Plaskett's Star: Two Views

The binary HD 47129, with a presumed record mass function f(M) = 12.6
M_\sun, has resisted consensus analysis since its discovery in
1922. The latest chapter began when one of us (Bagnuolo) participated
in a tomographic analysis of phase-separated UV spectra of the
individual components of the system, claiming reconstruction of
photospheric-like spectra of the individual components which were
analyzed by the usual methods. One of us (Underhill) criticized this
view, arguing that the strong wind features in the spectrum indicate
the existence of an almost optically thick wind/plasma surrounding the
system, mimicing Keplerian motion and photospheric features, and
thereby simulating an anomalously large mass function. Two of us
(Barry and Bagnuolo) have now attempted another tomographic analysis
of the system in the visible with data from our new 1-m
Multi-Telescope Telescope (MTT), and claim further support for our earlier
viewpoint.

We join the debate in its present form, and from the totality of the
recent high SNR spectra, present arguments regarding the structure of this
interesting system.